Pion elastic scattering from polarized 13c in the energy region of the [3, 3] resonance

A new development in polarized nuclear-target technology has made it possible to measure analyzing power, Ay, in pion elastic scattering from a polarized target.[1] Such measurements provide us with information on the isoscalar spin-flip strength of the nuclear transition which is very difficult to obtain otherwise. Differential cross sections, σ(Θ), for pion elastic scattering from nuclei with non-zero spin are dominated by the spin-independent (∆S = 0) amplitudes. Contributions from the spin-dependent (∆S = 1) amplitudes are usually negligible because σ(Θ) depends on the sum of the squares of those amplitudes. However, the Ay depend on the interference on the spin-independent and spin-dependent scattering amplitudes and are therefore quite sensitive to the spin-dependent forms.